Tensile test on polymer box

User discussions
1

GROMACS version:2022
GROMACS modification: No

Hi everyone,
I am trying to perform a tensile test on my polymer box in Z direction. Here is the related part of the mdp section :

pcoupltype = semiisotropic
tau_p = 1
compressibility = 4.5e-7 0
ref_p = 1 0
refcoord_scaling = com
deform = 0 0 1e-6 0 0 0

The box is comprised of two immiscible polymers and so I have interface. During the stretch, the phases are moving in direction of the stretch. How should I do the simulation to avoid moving chains?
Am i doing something wrong? Or do I need to do some extra things such as setting position restraints or etc. ?

2

Hi,

The deform code has been recently updated, so you may probably want to try the newest release.

In any case, I think this is the expected behaviour, given that the whole system gets ‘stretched’ in the direction of the deformation velocity. What would you expect otherwise?